Micromirror array lenses (MMAL) may be used in various types of optical devices, such as for example, imaging and display devices. However, because light rays are reflected according to the direction of the incident angle, to separate light input from light output of the MMAL and to deflect outgoing light to its intended direction, while not blocking incoming light, a beam splitter must be placed in the optical path. Use of the beam splitter makes the optical system more complex and degrades light efficiency, because in each path of the beam splitter, 50% of the light input is lost and while the other light input passes through the beam splitter twice.
FIG. 1 depicts a prior art optical system 100 using a micromirror array lens 103. The optical system includes a conventional refractive lens system 101, and a beam splitter 102 optically coupled to the conventional refractive lens system 101. The micromirror array lens 103 is optically coupled to the beam splitter 102. A focal plane 104 is optically coupled to the beam splitter 102. The focal plane 104 may be, for example, an image sensor or screen. Note that fifty percent of incident beams 105 are lost, as indicated by lost beams 106 and 107. Thus, 75% of the light is lost, causing the resultant image to appear dim.
Therefore, what is needed is an optical system using a micromirror array lens that provides improved light efficiency.